Existing unitized post tension systems for concrete masonry structures have until now required special other construction to address larger wall widths over approximately eight inches, to address horizontal decks and to address structural grade beams. The existing taught systems did not easily accommodate those needs in a unitized post tension system.
A. Introduction:
The prior art unitized post tension systems addressed methods and systems to improve the masonry systems. The new configurations of the invention presented here addressed the need to rapidly build the walls with for use as flat deck, wider wall systems and large grade beams. These needs are accomplished by configurations described below.
The recent prior art of a unitized post tension systems facilitated a clear improvement to traditional construction systems and their limitations. The recent system does not require special skills to construct; does not need water and power; does not require elaborate bracing; provides immediate occupancy or use; needs no curing time; and, is re-useable if desired since it is not destroyed when disassembled and moved. The recent system was an improvement to decrease the time to build or rebuild areas with minimal skilled labor. That system provides a far superior and more consistent strength structure than the traditional mortar constructed structure. While the prior art unitized post tension systems addressed many of the common requirements and limitations to traditional mortar and block construction methods, these systems still have room for improved devices and configurations to meet known shortcomings.
B. Problem Addressed:
The problems and limitations of the prior art unitized post tension systems are addressed generally for the use as flat deck, wider wall systems and large grade beams. In the building industry, the masonry, precast concrete and poured in place, tilt-up wall systems often accompany a building type—industrial, commercial, and hi-rise residential—where floor and roof decks are utilized. For example, motel and hotels and office buildings, strip malls and the like will incorporate precast decks or poured in place steel sheet metal and concrete to provide floors and roof decks. Therefore an alternative flat decking means from the unitized post tension system is desirable.
The unitized post tension system has also found acceptance in the southern building needs in Mississippi and Louisiana. In those locations, the rapid build system afforded by unitized post tension systems still had restrictions with the need for grade beams to be used in the quasi-marsh areas in cooperation with posts or pilings. Here the spans were of such lengths that some consideration for higher tension strength in the grade beams presented some challenges to the unitized post tension system. Therefore a better adapted and improved grade beam made of unitized post tension components with added features and capabilities is desirable.
The final desired improvement to unitized post tension systems is not an intuitively obvious need. In the concrete masonry unit (CMU) building systems, the approximately eight inch wide block is the main component. However, over the years, the need for ten inch, twelve inch and larger widths became evident. These were addressed by the industry to provide wide base walls. However, these wider block came at a price: they required all new, wider molds to produce; they were much heavier and usually required two people to lift and transport, and they often needed additional tooling and accessories to match the wider widths. Therefore, it is desirable to build wider, higher capacity wall systems from the unitized post tension components. The new system that addresses this will save the cost of molds, added labor and employee fatigue, and added costs for the wider blocks. However, the new use of the unitized post tension components would need to be as strong or even stronger than the CMU counterparts. These problems or limitations of the desires for the use as flat deck, wider wall systems and large grade beams are described below.
C. Prior Art:
Historically, no known devices have attempted to address the problem as stated. The building industry has made little progress for a unitized, post tension system so improvements to the recent unitized post tension systems have not yet been attractive to promotion of the technology. Even so, blocks have required very special and often complex configurations to even handle rods and plates and then they have taught only limit rods in special blocks. One such device is described in U.S. Pat. No. 5,511,902 (1996) issued to Center which teaches an instant levy block system. This is a complex, specially made block for constructing a levy, comprising a plurality of blocks, a plurality of connecting pegs, and a plurality of stakes. Each part is uniquely designed and made whereas the new use devices for mechanically secured block assembly systems uses a commonly made block designed for the common bars and bolts. Another block device is described in A U.S. Pat. No. 5,809,732 which was issued to Farmer, Sr. et al (1998) which teaches a masonry block with an embedded plate. The concrete masonry block has an external plate or plates that are anchored through the concrete masonry block. The external plates are cast into the concrete masonry block in the mold during casting. These plates and metal pieces are not taught as being part of a post tensioning system now shown cast within the hollow cavities as addressed by the improved new use devices for mechanically secured block assembly systems.
Another device for construction is taught by U.S. Pat. No. 6,098,357 issued to Franklin et al. (2000). This art discloses a modular pre-cast construction block system with a wall subsystem and a foundation subsystem. The wall subsystem has a number of wall units having cavities and pre-stressed tension cables are cast therein the cavity. This teaches precast walls and pass through cable which are specially made, require water, and are not readily re-useable like the new use devices for mechanically secured block assembly systems. A somewhat re-useable system is taught in the U.S. Pat. No. 6,178,714 issued to Carney, Jr. (2001). The long rods go through apertures in the specially cast block and the precast structures. No description of pre or post tensioning is taught or claimed. The configuration of special length rods, special blocks, special plates and a complex system that requires powered equipment to construct is unlike the new use devices for mechanically secured block assembly systems.
A Mortar less wall structure is taught in U.S. Pat. No. 6,691,471 issued to Price (2004). Here a wall structure comprising of columns of preformed, lightweight, stacked blocks, with the columns of blocks connected to each other by elongated, vertically oriented, support beams. Preferably, the wall structure is operatively connected to a structure by one or more brackets. The beams and blocks are special configuration, not readily available and with limited uses. These are complex and do not anticipate the new use devices for mechanically secured block assembly systems.
An interlocking, mortar less system is accomplished by some other devices. However, none of them are found to show a structural unitized post tensioning system as described for the new use devices for mechanically secured block assembly systems in the materials below. An example of one such interlocking device is taught by U.S. Pat. No. 4,640,071 issued to Haener (1987). This teaches a block of concrete or the like for use in constructing a mortar less wall. The device provided includes a spaced parallel pair of upright sidewalls having flat bottoms and tops and bearing integral block interlocking connectors and various configurations on their opposite ends. The sidewalls are integrally connected by means of these configurations. This is not the configuration taught by the new use devices for mechanically secured block assembly systems. Another mortar less system is taught by U.S. Pat. No. 3,296,758 by Knudsen (herein after referred to as “Knudsen”). Knudsen appears to discuss a set of superimposed building blocks with vertically spaced flat bars inter-fitted with the blocks and studs inserted through one bar and then threaded into engagement with bars of lower blocks. This Knudsen application fails to anticipate the present application for several reasons. Knudsen fails to teach or suggest each and every limitation of the claims of Harris, et al.
A unitized post tension system was issued to Marsh under U.S. Pat. No. 7,934,345. This basic mortar less system taught a masonry structure comprising a plurality of regular masonry blocks and/or bricks connected to each other by a plurality of metal bars and a plurality of standard metal threaded fasteners thereby forming a post tensioned structure. Preferably, the blocks are operatively connected to each other as a structure by simple mechanical tools. Each interconnection results in a unitized post tensioned member that, when interconnected to the adjacent members, forms a comparatively higher strength structure than systems made of mortar and reinforced mortar. The method used to create this structure is a simple, waterless, mortar less interconnection process that is completed by a series of simple individual steps of fastening the blocks and bars into a strong and durable structure. Once connected the structure is strong and durable. Another Unitized Post Tensioning System was taught by the patent application titled Unitized Post Tension Block System for Masonry Structures was filed in 2006 by Marsh et al and published as 2007-0186502 A1. What the present new use devices for mechanically secured block assembly systems herein entails is a configuration and means to improve the assembly of the Unitized Post Tensioned systems.
A heavy-duty super block system of solid block configurations and plates was filed by Marsh and published as US 2008-0098687 A1. It fails to address the new use devices for mechanically secured block assembly systems and in fact lacks the embodiment for the deck or grade beams. It also fails to garner the benefits of the multi-wall configuration. Another U.S. Pat. No. 8,099,918 was issued to Marsh et al for some bar changes but again fails to address the building system needs resolved by the present invention. Finally, another Marsh et al application was published by WIPO WO 2011/143248 for improved bar configurations. This application also fails to address the building system needs resolved by the present invention.
None of the prior art found with a rigorous search teaches all the features and capabilities of the new use devices for mechanically secured block assembly systems. As far as known, there are no systems at the present time which fully meet the need for a unitized, post-tensioned masonry block structure with the described shortfalls which are now resolved by the present invention. It is believed that this system is made with component parts, is built with simple tools, and provides a much stronger structure than prior art devices and systems.